The relay valve is a part of the automotive air brake system. In the braking system of trucks, the relay valve plays a role in shortening the reaction time and pressure establishment time.
The relay valve is used at the end of a long pipeline to quickly fill the brake chamber with compressed air from the air reservoir, such as in a trailer or semi trailer braking system.
Generally, differential relay valves are used. Prevent the simultaneous operation of the driving and parking systems, as well as the overlap of forces in the combined spring brake cylinder and spring brake chamber, thereby avoiding overloading of mechanical transmission components that can rapidly charge and exhaust the spring brake cylinder.
Operating principle of relay valve
The air inlet of the relay valve is connected to the air reservoir, and the air outlet is connected to the brake air chamber. When the brake pedal is depressed, the output air pressure of the brake valve is used as the control pressure input of the relay valve. Under the control pressure, the intake valve is pushed open, so that compressed air enters the brake air chamber directly through the intake port from the air reservoir without flowing through the brake valve. This greatly shortens the inflation pipeline of the brake air chamber and accelerates the inflation process of the air chamber. Therefore, the relay valve is also called an acceleration valve.
The relay valve generally adopts a differential relay valve to prevent simultaneous operation of the driving and parking systems, as well as overlapping forces in the combined spring brake cylinder and spring brake chamber, thereby avoiding overloading of mechanical transmission components that can rapidly charge and exhaust the spring brake cylinder. However, there may be air leakage, which is generally caused by the lax sealing of the intake or exhaust valves, and this is caused by damage to the sealing elements or the presence of impurities and foreign matters. Disassembly and cleaning or replacement of the sealing elements can solve the problem.
Post time: Mar-17-2023